Dyestuffs



Patented Aug. 15, 1,950

UNIT-ED PATENT OFFICE l n En CYAZ Er D YESTUFFS John Dayid Kendall and Frank Peter Doyle, Ilford, England, assignors to Ilford Limited,

liford; England, a British company NoD rawin'g. Application June a, 1948, Serial Nd. 30,975. In Great Britain m 4, 194': f

tomerocyanine dyeis aw t P epar d b 6 Claims. (01. 260 2404;

wherein R1 is an alkyl, hydroxyalkyl, arallryl-or hydroityaralkylgroup, R2 is ahydrog'exiatom ora hydrocarbongroup', Dris the're'sidue of "a five membered 'or siir-iiienib'ered' heteroc'ycli'c 'n'itto gen rin Q is an oxygen atom or a sulphur atom,- and n is nought or one, with an acid *HX' w'here'X is the acid anion and a t'rithio ort'fiofori'nate- HC(SR3)3 where R: is an alkyl or aralkyl group, the reaction being effected in the presence of a carboxylic acid or anhydride which isa solvent for the reacting materials. r

The product of the reaction is believed to be a compound of the general Fdrmula 11:

AB: II

h 'In tu we; may be ethyl, in which case the reagent employed is triethyl trithio-orthoformate which. is the most readil obtainable cqmpound ofthe series. However, it is -disclosed that it may be any other alkyl grouper 'aralkyl'group, e'ig. tribenzyl trithio-orthoformate.

The acid HX may be any strong acid, but the hydrohalic acids, e. g. H01 and Hbr, and p-toluene sulphonic acid, are preferred. The solvent acid or anhydride is preferably a weak acid, e. g. acetic acid or acetic anhydride.

The reaction should be effected under substantially' anhydrous conditions, i. e. in the absence of any hydrolytic substance, and is best efiected by heating the reagents together.

The residue D1 may be selected from the residues of thiazoles, oxazoles, selenazoles and their polycyclic homologues, such as those of the benzene, naphthalene, acenaphthene and anthracene series, pyridine and its polycyclic homologues such as quinoline and a and 3 naphthaquinolines, lepidines, indolenines, diazines, such as pyrimidines and quinazolines, diazoles (e. g. two-5.18- diazole) oxazolines, thiazolines and selenazolines; The polycyclic compounds of, this series may also be'substituted in the carbocyclic rings with one or more groups such' as: alkyl, aryl, amino, 'hydroxy, 'allgoxy and methylenedioxy groups; or byhal'ogen atoms.

Accordin to, the present invention trinuclear polyinethine merocyanine dyestuflfs are obtained by"r'acting a compoundof general Formula II with a heterocyclic nitrogen compound -contain-'- ing a; reactive methylene group. pounds may be (1;) compounds of the general Fonnula Such eon;-

group and Y is an acid'radicle, and'the'cdfl responding methylene bases of the general Formula IV:

I" '1 i rcn=on). =CHR4 s IV (1)) compounds of the general Formula V:

Q-C=S HaC I c o-N-R. v

where Q is an oxygen atom or a, sulphur atom and Re is a hydrogen atom or a hydrocarbon group.

The products obtained by the use of compounds of type (a) have the general Formula VI:

The products obtained by the use of compounds of type (b) have the general For- Compounds of type (a) which may be employed may be any of those which have been used or proposed for use in the many processe for the production of cyanine and similar dyestufis, for example, thiazoles, oxazoles, selenazoles and their polycyclic homologues such as those of the benzene, naphthalene, acenaphthene and anthracene series; pyridine and its polycyclic homologues such as quinoline and a and-p naph- 5 thaquinolines; lepidines; indolenines, diazines, such as pyrimidines and quinazolines; diazoles (e. g. thio-fifi'-diazole); oxazolines, thiazolines and selenazolines. The polycyclic compounds of these series may also be substituted inthe carbocyclic rings with one or more groups such as alkyl, aryl, amino, hydroxy', alkoxy and methylene-dioxy groups, or by hologen atoms.

Compounds of type (b) which may befemployed are rhodanic acid and oxarhodanic acid and the N-hydrocarbon substitution derivatives.

of these compounds.

The formation of the dyestuffs is readily efiected by heating the reagents together in the presence of a solvent and a base, e. g. pyridine, piperidine, diethylamine, triethylamine and triethanolamine, or an inorganic basesuch as a solution of sodium or sodium acetate in ethyl alcohol.

Where the dyestuff is obtained in the form of a sulphate or an alkyl-p-toluene sulphonate, it may be converted to a salt of another acid by treatment with a solution of an alkali salt of such other acid, e. g. potassium chloride, potassium bromide or potassium iodide.

The following examples, in which the parts are by weight, serve to illustrate this invention:

EXAMPLE 1 Preparation 0 [2- (3-ethyl-benzthiazole) (3- ethyl 2 thio 4 keto tetrahydrothiazole) 'y.2"-(1-ethg Z quinoline) tetramethine merocyanine] iodide 1 ethylthio 2 c quinolyl 3 [3 ethyl- 2' thio 4-keto-tetrahydrothiazolylidenel propene ethiodide (5 parts) (prepared as in Example 2 of Ser. No. 30,979 filed on even date herewith, and 2-methyl benzthiazole ethiodide (3 parts) were boiled together in pyridine (100 parts) for ten minutes. The blue solution was then poured into water, cooled and. diluted, the precipitated dyestuiI-being removed hyv -filtration and washed. Crystallisation :"fro'm methyl alcohol gave tiny blue crystals, M. Pt. 216 (with decomposition) of a .dye having the following structural formula:

EXAMPLE 2 c; 1 ethylthio 2 -1 as dimethyl indolenyl) -3- (3f ethyl- 2 thio 4 keto tetrahydrothiazolylidene) propene metho-p-toluene sulphonate (prepared as in Example 4 of Ser. No. 30,979 filed on even. date herewith), was reacted with 2- cmethyl benzthiazole ethiodide as in Example 1. The product. after boiling out with benzene, gave a dark green powder, M. Pt. 240 (with decomposition) {This product was a dye having the following structural formula:

05$ om- CH:

propene ethiodide (prepared as Example 5' of Ser. N0.,30,9 79 filed'on even date herewith) was reactedwith 2- rnethyl1 benzthiaz j'ole thiodide I I as in'Ex'ample'l; The product, aiter boilin out 1 tet'rawith benzene, gave dar s num eneedles, 280 (with decomposition) of a dye having the followin structural formula:

Preparation of [Z-(I-ethyL quinolino) -'-(3- ethyl 2 thio 4 keto tet'rwhydrothiazole) #2" (I -ethyl quinoline) tetmmethine-cydninel iodide 1 This dyestuff was prepared fromthe intermediate of Example 2 of Ser. No. 30,979 filed on even date herewith (the crude. p-ltoluene sill-11111 17.

nate being used before conversion to the=iodide)- by reaction with quinoline ethiodide as in Example 1. The dyestuff was isolated as green crystals with a gold reflex, M. Pt. 204 (with decomposition) and had the following structural formula:

Preparation of bis 5 (3 ethyl 2 thz'o 4- keto-tetmhydrothiazole) fl2'(1 eth'yl dihydro-quinoline) -trimethine merocyanine This was prepared by the reaction of the intermediate of Example 2 of Ser. No. 30,979 filed on even date herewith (the p-toluene sulphonate salt being used directly) with 3-ethyl-2-thio-4- keto-tetrahydrothiazole as in Example 1. The dyestufl was isolated as dark brown crystals,

M. Pt. 273 (with decomposition) and had the following structural formula:

What we claim is:

1. Process for the production of trinuclear polymethine merocyanine dyestufis which comprises reacting a compound of general formula:

where-Rm is.-select e.d from the class consisting of alkyl. hydrox a kvl, .acy 0xya1 x ,,.;ara1ky1, ydroxyaralkyl and aeyl yaralkl gr upsiikz is-a;

where R1 is selected from the class consistingo allryl, hydroxyalkyl; acyloxyalkyl, aralkyl, h droxyar'alkyl' and acyloxyaralkl groups, R2

selected from the class consisting of the hdroglejnf'i atom and hydrocarbon groups, R: is selected from the" class" consisting of 'alkyl and araikyi groups, X is an acid radicle, Q is selected from the class consisting of oxygen and sulphur atoms, n is selected from nought and one, and D1 is a residue of a nucleus selected from the class consisting of five-membered and six-membered heterocyclic nitrogen nuclei, with a compound selected from the class consistin of quaternary salts of the general formula:

where D2 is selected from the same class as D1. R4 is selected from the same class as R2, R5 is selected from the same class as R1, n is selected from nought and one and Y is an acid radicle, and the corresponding methylene bases.

3. Process for the production of trinuclear polyinethine merocyamne dyestufis which comprises reacting a compound of general formula:

where R1 is selected from the class consisting of alkyl, hydroxyalkyl, acyloxyalkyl, aralkyl, hydroxyaralkyl and acyloxyaralkyl groups, R2 is selected from the class consisting of the hydrogen atom and hydrocarbon groups, R3 is selected from the class consisting of alkyl and aralkyl groups, X is an acid radicle, Q is selected from the class consisting of oxygen and sulphur atoms, n is selected from nought and one and D1 is a residue of a nucleus selected from the class consisting of five-membered and six-membered heterocyclic nitrogen nuclei, with a compound of the general formula:

CON-Ra where Q is selected from the class consistin of the oxygen atom and the sulphur atom and Re is selected from the class consisting of the hydrogen atom and hydrocarbon groups.

.4. Process according to claim 1 wherein the reaction is efiected by heating the reagents together in the presence of a. base.

5. A dyestufi or the general formula:

from nought and one. X is an acid radicle and D1 and Dz areeach a. residue of a nucleus selected fromthe class consisting of five-membered and six-membered heterocyclic nitrogen nuclei.

6. The dye of the formula:

Cl Hl I oUN/ p} :H! CaHrN 8 JOHN DAVID KENDALL.

-FRANK PETER DOYLE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,385,815 Kendall Oct. 2, 1945 2,397,013 Kendall Mar. 19, 1946 FOREIGN PATENTS Number Country Date 549,202 Great Britain 1942 

6. THE DYE OF THE FORMULA: 